IntelliSense questions

[diegoherranz]

I watched your talk at at EOSS 2023 and I found it very useful. Thanks for that!
I was already using VSCode + CortexDebug but I certainly learnt a few new tricks.

I saw you define these two to improve IntelliSense:

// IntelliSense
"C_Cpp.default.compilerPath": "${userHome}/zephyr-sdk-0.16.1/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc",
"C_Cpp.default.compileCommands": "${workspaceFolder}/build/compile_commands.json",

A couple of questions:

1. What does compilerPath "improve"? I can see compileCommands making a big difference, for instance I can see all the defines correctly hinted/highlighted. But I can't see any change whether I define compilerPath or not. What is it supposed to do?
2. Regarding compileCommands, it works great on .c files but it doesn't work on .h files since they are not part of compile_commands.json. Have you found a way to make it work on .h files too?

Many thanks!